Drawing Velocity Time Graphs from Position Time Graphs Uniform and Non-Uniform Motion

How can we use d-t graphs to determine v- t graphs? Find the velocity for each section of the graph and plot it (make a list of points).

Think about… Sketch a position-time graph of each object listed below. Describe its slope as positive or negative, and as constant, increasing, or decreasing. A) a stone at rest B) a jogger moving steadily to the right C) a bicycle moving to the left and slowing down D) a rocket moving up at an increasing speed E) a stone falling freely with increasing speed F) a parachutist drifting down at a steady speed

Non-Uniform Motion An object does not always move at a constant speed. You may speed up or slow down. Non-uniform motion, when graphed, appears as a curve not a straight line.

Instantaneous Velocity When you are driving on the highway and you look down at your speedometer, you are traveling at + 55 km/h. At that instant in time, + 55 km/h is your instantaneous velocity. For uniform motion, your instantaneous velocity is the same as you average velocity. For non-uniform motion, your instantaneous velocity changes.

Finding Instantaneous Velocity from a Graph (Uniform Motion) To find instantaneous velocity on a uniform position- time graph, just find the average velocity for the given segment.

Finding Instantaneous Velocity from a Graph (Non-Uniform Motion) To find instantaneous velocity on a non- uniform position-time graph, draw a line that is tangent to the curve at that point. The slope is the instantaneous velocity (take the two points on the tangent from each side of the point).

Instantaneous Velocity (Non- uniform Motion)

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